Tubs and showers, like everything else in this world, eventually come to the end of their aesthetic and practical life. Finishes become abraded by years of exposure to water, household cleaners, and everyday use. The abrasion leads to pitting, staining and, for metal tubs, corrosion.

Water: the root of all evil

Frequently, the wall and floor areas immediately surrounding the tub become degraded. Flaws invisible to the naked eye permit migration of water to the support structures directly behind the finished surfaces. Water attacks building materials the way nothing else can.

Would wood last forever?

Wood products of every type swell and shrink with the rise and fall of water content. With each swell-shrink cycle, the wood grain loses its strength. In surprisingly short order the weakened component is no longer capable of providing stationary support. Every time a person walks by, or bumps into a wall, or closes a door, the minute vibrations act to wreck watertight seals and fatigue finished surfaces.

Water also causes wood to rot, whether continuously or intermittently exposed. It is this type of activity that can often be seen on the floor at the ends of the tub, where water is likely to escape the confines of the shower curtain. If you step on the floor by the head of the tub and feel sponginess under foot, it is an indication of wood rotted by water exposure.

Drywall: mush waiting to happen

Water degrades gypsum board (i.e., drywall, “sheetrock”) quickly and irreversibly. Even water resistant “green board”, which is gypsum board on steroids, cannot withstand the patient onslaught of water. In homes of a certain age, gypsum board is what lies behind the ceramic tiles of bath and shower walls.

Gypsum acts like a sponge. If water leaks through a tiny pin hole in a grout line, it gets sucked in all directions, including UP, by the porous and thirsty drywall. The wet gypsum looses strength as it expands. The expansion movement causes further failure of grouted joints. The further failure of the grout joints permits greater leakage. And on, and on, and on. . .

Last, but not least

Let us not forget that the mortars and glues that hold the ceramic tiles or fiberglass panels onto the wall depend on two dimensional points of contact with each opposing surface. Unlike screws or nails which penetrate multiple layers of materials, adhesives and cements are only as strong as the faces to which they cling. If one face is wet gypsum that has turned to mush, or wet wood that has turned to rot, the fastening strength is greatly diminished. This is when you begin to see tiles dropping off the wall, or fiberglass panels separating.

Eventually (really, just the blink of the eye to a water droplet), adhesives, caulks and grouts begin to fail in a slow motion cascade of dilapidation. Every loss of integrity to a bathroom surface hastens further demise.

What can I, the innocent homeowner, do about this tragedy?

The trick is to keep water from coming into contact with the underlying materials in the first place. Therein lies the rub.